1. Field of the Invention
This invention relates to phase shifters and, more specifically, to a ferrite scanning line source, particularly for use in conjunction with a phased array.
2. Brief Description of the Prior Art
Phase shifters in the prior art are considered as a single phase shifting element, generally a loaded ferrite waveguide, configured with one RF input port and one RF output port for RF energy. Insertion characteristics of the ferrite material are controlled with a driver circuit providing a current passing through the ferrite material, causing a precisely controlled phase shift of the output signal. The output signal is utilized to drive, as required, each element in, for example, a phased array. A separate phase shifter as described is required for each element of the phased array.
In accordance with the prior art, the elements of a phased array have been controlled by a transmit/receive (T/R) module or other costly device connected to each element of the phased array. The T/R modules provide the transmit signal to be radiated and a receiver function for the returned signal. One T/R module driving each antenna element provides the maximum antenna steering control. However, T/R modules are costly. It follows that a system which uses fewer components and is less expensive is highly desirable.